/* 
 * FreeModbus Libary: A portable Modbus implementation for Modbus ASCII/RTU.
 * Copyright (c) 2006-2018 Christian Walter <cwalter@embedded-solutions.at>
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. The name of the author may not be used to endorse or promote products
 *    derived from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 *
 */

/* ----------------------- System includes ----------------------------------*/
#include "stdlib.h"
#include "string.h"

/* ----------------------- Platform includes --------------------------------*/
//#include "port.h"

/* ----------------------- Modbus includes ----------------------------------*/
#include "..\Inc\DjyMB.h"

/* ----------------------- Defines ------------------------------------------*/
#define MB_PDU_FUNC_READ_ADDR_OFF           ( MB_PDU_DATA_OFF )
#define MB_PDU_FUNC_READ_REGCNT_OFF         ( MB_PDU_DATA_OFF + 2 )
#define MB_PDU_FUNC_READ_SIZE               ( 4 )
#define MB_PDU_FUNC_READ_REGCNT_MAX         ( 0x007D )

#define MB_PDU_FUNC_READ_RSP_BYTECNT_OFF    ( MB_PDU_DATA_OFF )

/* ----------------------- Static functions ---------------------------------*/
u16    prveMBError2Exception( u16 eErrorCode );

/* ----------------------- Start implementation -----------------------------*/
#if MB_FUNC_READ_INPUT_ENABLED > 0

u16
eMBRegInputCB( DS_MB_Chn * MB_Chn, u8 * pucRegBuffer, u8 usAddress, u8 usNRegs )
{
    u16   eStatus = MB_ENOERR;
    int      iRegIndex;

    if( ( usAddress >=  MB_Chn->Set->MB_Add_Sta )
        && ( usAddress + MB_Chn->Set->Data_Offset + usNRegs <= MB_Chn->Set->MB_Add_Sta + MB_Data_Num ) )
    {
        iRegIndex = ( int )( usAddress - MB_Chn->Set->MB_Add_Sta );
        Int_SaveAsynSignal() ;
        while( usNRegs > 0 )
        {
            *pucRegBuffer++ = ( unsigned char )( MB_Chn->MB_Data[iRegIndex] >> 8 );
            *pucRegBuffer++ = ( unsigned char )( MB_Chn->MB_Data[iRegIndex] & 0xFF );
            iRegIndex++;
            usNRegs--;
        }
        Int_RestoreAsynSignal() ;
    }
    else
    {
        eStatus = MB_ENOREG;
    }

    return eStatus;
}


u16
eMBFuncReadInputRegister( DS_MB_Chn * MB_Chn )
{
    u16          usRegAddress;
    u16          usRegCount;
    u8          *pucFrameCur;

    u16    eStatus = MB_EX_NONE;
    MB_Err    eRegStatus;

    u8 * pucFrame ;
    u16  usLen  ;
    usLen = MB_Chn->length ;
    pucFrame = MB_Chn->MB_PDU ;

    if( *usLen == ( MB_PDU_FUNC_READ_SIZE + MB_PDU_SIZE_MIN ) )
    {
        usRegAddress = ( u16 )( pucFrame[MB_PDU_FUNC_READ_ADDR_OFF] << 8 );
        usRegAddress |= ( u16 )( pucFrame[MB_PDU_FUNC_READ_ADDR_OFF + 1] );
        usRegAddress++;

        usRegCount = ( u16 )( pucFrame[MB_PDU_FUNC_READ_REGCNT_OFF] << 8 );
        usRegCount |= ( u16 )( pucFrame[MB_PDU_FUNC_READ_REGCNT_OFF + 1] );

        /* Check if the number of registers to read is valid. If not
         * return Modbus illegal data value exception. 
         */
        if( ( usRegCount >= 1 )
            && ( usRegCount < MB_PDU_FUNC_READ_REGCNT_MAX ) )
        {
            /* Set the current PDU data pointer to the beginning. */
            pucFrameCur = &pucFrame[MB_PDU_FUNC_OFF];
            *usLen = MB_PDU_FUNC_OFF;

            /* First byte contains the function code. */
            *pucFrameCur++ = MB_FUNC_READ_INPUT_REGISTER;
            *usLen += 1;

            /* Second byte in the response contain the number of bytes. */
            *pucFrameCur++ = ( u8 )( usRegCount * 2 );
            *usLen += 1;

            eRegStatus =
                eMBRegInputCB(MB_Chn , pucFrameCur, usRegAddress, usRegCount );

            /* If an error occured convert it into a Modbus exception. */
            if( eRegStatus != MB_ENOERR )
            {
                eStatus = prveMBError2Exception( eRegStatus );
            }
            else
            {
                *usLen += usRegCount * 2;
            }
        }
        else
        {
            eStatus = MB_EX_ILLEGAL_DATA_VALUE;
        }
    }
    else
    {
        /* Can't be a valid read input register request because the length
         * is incorrect. */
        eStatus = MB_EX_ILLEGAL_DATA_VALUE;
    }
    return eStatus;
}

#endif
